Filter housing with filter key attachment

ABSTRACT

A filter assembly for fluid filtration having a push-activated lock and release mechanism. A push filter design activates a filter key lock upon insertion and extraction, where the filter key may be used simultaneously as a lock and as an identifier for particular filter attributes. The filter housing assembly may be attached to, and removed from, a filter base by a push-actuated release. Upon insertion, the filter key shifts the filter lock longitudinally to receive interlocking segments. Upon extraction, the same axial push shifts the filter lock further to align the interlocking fingers within gaps that allow for easy extraction. The specific key lock design allows a user to identify and match certain filter configurations received by the mechanical support, and reject other filter configurations.

BACKGROUND OF THE INVENTION 1. Field of the Invention

This invention relates to a filtering apparatus, specifically a filterhousing apparatus to facilitate easy removal and replacement of a filterhousing from a mechanical support, and more specifically, to a pushfilter design that activates a floating key lock, where the key may beused simultaneously as a lock and as an identifier for particular filterattributes. The mechanical support may be situated inline, and in fluidcommunication, with influent and effluent piping, such as within arefrigerator. More specifically, the invention relates to a filterhousing and mount, whereby the filter housing may be attached to, andremoved from, the mount by a push-actuated release. A controlledattachment or detachment of the filter sump, containing the filtermedia, is activated by the axial push of the sump towards the mechanicalsupport. The specific key lock design allows a user to identify andmatch certain filter configurations received by the mechanical support,and reject other filter configurations. An internal shutoff, activatedby the push-actuated release, blocks spillage during filter housingremoval and replacement.

2. Description of Related Art

The invention relates to a water filtration system having a locking andunlocking mechanism for changing the filter when the filter media hasserved its useful life. The use of liquid filtration devices is wellknown in the art as shown in U.S. Pat. Nos. 5,135,645, 5,914,037 and6,632,355. Although these patents show filters for water filtration, thefilters are difficult to replace owing to their design and placement.For example, U.S. Pat. No. 5,135,645 discloses a filter cartridge as aplug-in cartridge with a series of switches to prevent the flow of waterwhen the filter cartridge is removed for replacement. The filter must bemanually inserted and removed and have a switch activated to activatevalve mechanisms so as to prevent the flow of water when the filter isremoved. The cover of the filter is placed in the sidewall of arefrigerator and is employed to activate the switches that activate thevalves. The filter access is coplanar with the refrigerator wall andforces an awkward access to the filter cartridge.

In U.S. patent application Ser. No. 11/511,599 filed on Aug. 28, 2006,for Huda, entitled “FILTER HOUSING APPARATUS WITH ROTATING FILTERREPLACEMENT MECHANISM,” a filter assembly having a rotator actuatingmechanism including a first internal rotator and a second internalrotator is taught as an efficient way to insert, lock, and remove thefilter housing from its base. A simple push mechanism actuates theself-driving release and change over means that hold and release thefilter housing sump, and provide influent shutoff to prevent leaking andspillage. Rotational shutoff and locking mechanisms are activated andreleased by axial force on the filter housing at the commencement of thefilter changing procedure.

The instant invention is particularly useful as the water filteringsystem for a refrigerator having water dispensing means and, optionally,an ice dispensing means. The water used in the refrigerator or water andice may contain contaminants from municipal water sources or fromunderground well or aquifers. Accordingly, it is advantageous to providea water filtration system to remove rust, sand, silt, dirt, sediment,heavy metals, microbiological contaminants, such as Giardia cysts,chlorine, pesticides, mercury, benzene, toluene, MTBE, Cadmium bacteria,viruses, and other know contaminants. Particularly useful water filtermedia for microbiological contaminants include those found in U.S. Pat.Nos. 6,872,311, 6,835,311, 6,797,167, 6,630,016, 5,331,037, and5,147,722, and are incorporated herein by reference thereto. One of theuses of the instant filter apparatus is as a water filtration apparatusfor a refrigerator. Refrigerators are appliances with an outer cabinet,a refrigeration compartment disposed within the outer cabinet and havinga rear wall, a pair of opposing side walls, at least one door disposedopposite the rear wall, a top and a bottom and a freezer compartmentdisposed in the outer cabinet and adjacent to the refrigerationcompartment. It is common for refrigerators to have a water dispenserdisposed in the door and in fluid communication with a source of waterand a filter for filtering the water. Further, it is common forrefrigerators to have an ice dispenser in the door and be in fluidcommunication with a source of water and a filter for filtering thewater. It has been found that the filter assembly of the instantinvention is useful as a filter for a refrigerator having a waterdispenser and/or an ice dispenser.

SUMMARY OF THE INVENTION

The present invention is directed to, in a first aspect, a filterhousing assembly comprising: a filter housing for enclosing a filtermedia, the filter housing having a body and a top portion for forming afluid-tight seal with the body, the filter housing including: an ingressport; an egress port; and a filter key located on the filter housing andhaving a top surface, longitudinal sides, and lateral sides, the filterkey including a plurality of spaced protrusions or fingers on eachlongitudinal side of the filter key extending laterally from the lateralsides approximate the top surface, wherein the fingers include wingedextensions for mating attachment to a filter base or manifold.

The filter housing includes an elongated protrusion extendinglongitudinally from a side surface of the filter housing body portion, aside surface of the top portion, or both.

The filter key includes a groove complementary to the elongatedprotrusion for insertably securing the filter key to the filter housingby slideably mating the elongated protrusion of the filter housingwithin the filter key groove. The fingers may include slanted or angledfaces and/or a diamond shaped cross-section. The filter key may beattached to the filter housing by snap fit, friction fit, welding, orbonding.

A filter manifold or base is releasably attachable to the filterhousing, the filter manifold or base comprising an attachment structurefor fixably receiving the spaced protrusions or fingers of the filterkey.

The ingress or egress ports extend radially from a side surface of thefilter housing body portion, a side surface of the top portion, or both,and may be off axial center of the filter housing.

The spaced protrusions or fingers are integrally formed with the filterkey.

The filter housing assembly may include at least one strengthening ribon the filter housing body. The at least one strengthening rib protrudesradially from the filter housing body and extends longitudinallyintermediate between top and bottom portions of the filter housing.

The filter key may further include an indented angled ramp segment on atleast one bottom edge, and the filter housing includes at least oneprotruding or extended angled ramp segment for complementary mating withthe indented angled ramp segment on the filter key.

In a second aspect, the present invention is directed to a filterhousing assembly comprising: a filter housing for enclosing a filtermedia; a filter housing having two ports for ingress and egress in fluidcommunication with the filter media, the filter housing having a filterhead forming a fluid-tight seal with the filter housing and a firstattachment structure for receiving a filter key; and the filter keyhaving a top surface, a bottom, longitudinal sides, and lateral sides,the filter key including: a plurality of spaced protrusions or fingerson each longitudinal side of the filter key extending laterally from thetop surface and having winged extensions; and a second attachmentstructure located on the filter key bottom for attaching the filter keyto the first attachment structure on the filter housing.

The filter key is fixably or removably attached to the filter housing.The filter key fingers include slanted or angled faces on the wingedextensions. The winged extensions have a diamond shaped cross-section.

The first attachment structure includes an elongated protrusionextending from the filter housing, and the second attachment structureincludes a groove complementary to the elongated protrusion forinsertably securing the filter key to the filter housing by slideablymating the elongated protrusion of the filter housing within the groove.

The filter housing assembly is further adapted to be releasablyconnected to a filter base, wherein the filter base comprises: a baseplatform having fluid ingress and egress ports; and a floating lock insliding communication with the base platform, having a bottom surface, atop surface, and longitudinal and lateral sides, the floating lockincluding: spaced protrusions, drive keys, or fingers on thelongitudinal sides extending laterally inwards, including at least oneshaped protrusion, finger, or drive key for slideably contacting thecomplementary mating filter housing assembly, the at least one shapedprotrusion, finger, or drive key including an angled face exposedtowards the bottom surface.

The floating lock includes a position stop centered about the lateralsides, and located above the at least one drive key to provide aphysical stop during insertion of the complementary mating filter key.The key includes a track structure longitudinally across the floatinglock.

In a third aspect, the present invention is directed to a filter base incombination with a filter housing assembly, the combination comprising:a filter base having an ingress port and an egress port on a baseplatform; a slideable floating lock in slideable contact of the filterbase, the floating lock having a plurality of drive keys or lateralextensions separated by gaps; a resilient member in contact with thefloating lock, providing a retraction force for the floating lock; afilter housing assembly including a longitudinal side portion and a topportion having a filter head, a first attachment structure and anelongated protrusion extending from the longitudinal side portion or aside of the top portion or both, and at least one protruding angled rampsegment for complementary mating with the angled ramp segment on thefilter key; and a filter key located on the filter housing assembly, thefilter key having longitudinal sides and lateral sides, the filter keyincluding: a plurality of spaced protrusions or fingers on eachlongitudinal side of the filter key extending laterally from the topsurface, wherein the fingers include winged extensions having slanted orangled faces for mating attachment to a filter base or manifold; asecond attachment structure having a groove complementary to theelongated protrusion for insertably securing the filter key to thefilter head top surface by slideably mating the elongated protrusion ofthe filter head within the groove; and an indented angled ramp segmenton at least one bottom edge.

The floating lock includes: a bottom surface, a top surface, andlongitudinal and lateral sides, and wherein the lateral extensionsinclude drive keys on the longitudinal sides extending laterally inwardsat the bottom surface for slideably receiving the filter key, each ofthe drive keys including an angled portion exposed towards the bottomsurface, and an edge or wedge on each of the drive key bottom forreleasably contacting with a portion of the filter key; and a positionkey centered about the floating lock, and located above the drive keysto provide a physical stop during insertion of the filter housingassembly.

It is an object of this invention to provide a filter housing apparatusmounted to a base and having an automatic locking mechanism for simplereplacement and removal.

It is an object of this invention to provide a filter housing apparatusand base attached by a push activated, slideably moveable, floatinglock.

It is another object of this invention to provide a filter housingapparatus mounted on a surface having non-rotating locking means withpressure activation for replacement and removal.

It is another object of the present invention to provide a filterhousing apparatus that allows for a keyed identification of the filter.

It is a further object of this invention to provide a filter housingapparatus for use with water dispensing and\or ice dispensing apparatuswhereby filtered water is provided to the water dispensing and/or icedispensing apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the invention believed to be novel and the elementscharacteristic of the invention are set forth with particularity in theappended claims. The figures are for illustration purposes only and arenot drawn to scale. The invention itself, however, both as toorganization and method of operation, may best be understood byreference to the description of the preferred embodiment(s), whichfollows, taken in conjunction with the accompanying drawings in which:

FIG. 1A is a top exploded view of one embodiment of the filter assemblyof the present invention;

FIG. 1B is a side plan view the embodiment of the filter housingassembly of FIG. 1A;

FIG. 1C depicts a perspective view of the filter housing assembly withstrengthening ribs extending at least partially down the outer surfaceof the filter housing;

FIG. 2A is a perspective view of one embodiment of the filter key of thepresent invention;

FIG. 2B is a lateral side view of the filter key of FIG. 2A;

FIG. 2C depicts a bottom plan view of the filter key of FIG. 2A showinga groove and a locking nub or tab for attachments;

FIG. 2D depicts a perspective view from the opposite side of the filterkey of FIG. 2C;

FIG. 2E depicts a bottom view of the filter key of FIG. 2A;

FIG. 2F is a longitudinal side view of the filter key of FIG. 2A;

FIG. 2G depicts a slotted groove which includes a wider upper portionfor securely affixing the filter key to the filter head or filtermanifold;

FIG. 2H is a side view of the filter key depicting an angled, rampsegment, which at least partially extends the length of the bottomsurface of the filter key;

FIG. 2I depicts the complementary angled ramp segment for the filter keyof FIG. 2H;

FIG. 2J depicts a side view of a partial section of the filter headshowing a mating protrusion for interlocking with the slotted groove onthe filter key, and complementary angled ramp segments for interlockingwith the ramp segments on the filter key bottom edges;

FIG. 3A depicts a perspective view of one embodiment of the floatinglock or sliding lock of the present invention;

FIG. 3B is a perspective view from the opposite side of the floatinglock of FIG. 3A;

FIG. 3C is a lateral side view of the floating lock of FIG. 3A;

FIG. 3D depicts a top view of the floating lock of FIG. 3A;

FIG. 3E depicts cross-sectional longitudinal side view of the floatinglock of FIG. 3A;

FIG. 4A is a perspective view of one embodiment of the filter manifold;

FIG. 4B is a top plan view of a second embodiment of the filter manifoldwith an extension support member;

FIG. 4C is a perspective view of a second embodiment of the filtermanifold;

FIG. 5A is a side view of one embodiment of the filter head of thepresent invention;

FIG. 5B is a bottom perspective view of the filter head of FIG. 5A;

FIG. 5C is a top perspective view of the filter head of FIG. 5A;

FIG. 5D is another embodiment of the filter head with a snap fit lockfor the filter key;

FIG. 5E is a bottom perspective view of the filter head of FIG. 5D;

FIG. 5F is a top perspective view of the filter head depicting theaperture for receiving the filter key;

FIG. 5G depicts a one-piece or integrated filter head/filter manifoldconstruction having ingress and egress ports for fluid flow;

FIG. 5H is a side view of the integrated, one-piece filter head of FIG.5G;

FIG. 5I is a bottom view of the integrated, one-piece filter head ofFIG. 5G, depicting an off axial center cylinder for receiving an end capport of the filter cartridge;

FIGS. 6A and 6B are exploded views of a second embodiment of the filterassembly of the present invention, showing a filter key having anextended boss;

FIG. 7A is a top perspective view of an embodiment of the filter key ofthe present invention having an extended boss;

FIG. 7B is a bottom perspective view of the filter key of FIG. 7A;

FIG. 7C depicts a top plan view of the filter key of FIG. 7A;

FIG. 7D depicts a side plan view of the filter key of FIG. 7A;

FIG. 7E depicts an end or lateral side view of the embodiment of thefilter key of FIG. 7A, showing the boss rising above the plane createdby the fingers, and two wings extending laterally outwards from theboss;

FIG. 7F is a perspective view of another embodiment of the filter key ofthe present invention showing a locking nub located on the bottomportion on a lateral side;

FIG. 8A depicts a perspective view of an embodiment of the floating lockof the present invention;

FIG. 8B is a top view of the floating lock of FIG. 8A;

FIG. 8C is a cross-sectional view of the floating lock of FIG. 8Adepicting a drive key located at one end of the floating lock on thelongitudinal or side panel;

FIG. 8D depicts an exploded view of the drive key of FIG. 8C showing theedge angle and face;

FIG. 8E depicts a perspective view of a floating lock having anextension member;

FIG. 8F is a side view of the floating lock of FIG. 8E having anextension member;

FIG. 8G is a lateral or cross-sectional view of the floating lock ofFIG. 8E with an extension member;

FIG. 9A is a perspective view of a non-floating port of the presentinvention;

FIG. 9B is a top plan view of the non-floating port of FIG. 9A;

FIG. 10A is a top plan view of one embodiment of the rear plate of thepresent invention;

FIG. 10B is a bottom perspective view of the rear plate of FIG. 10A;

FIG. 10C is a top plan view of a second embodiment of the rear plate ofthe present invention;

FIG. 11 is an exploded view of a filter assembly of the presentinvention, showing a filter key having a boss, connected to a filtermanifold having extension supports;

FIG. 12A is a side view of a filter housing assembly having a radiallyremovable, detachable filter cartridge or sump of the filter assembly ofthe present invention;

FIG. 12B depicts a top view of the filter housing assembly of FIG. 12Awith radially projecting ingress and egress ports; and

FIG. 12C depicts a perspective view of filter housing assembly of FIGS.12A and 12B radially attached to a filter base, which includesnon-floating port and rear plate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

In describing the preferred embodiment of the present invention,reference will be made herein to FIGS. 1 to 12 of the drawings in whichlike numerals refer to like features of the invention. Features of theinvention are not necessarily shown to scale.

The present invention is directed to a filter housing assembly forfiltration of liquids, including the interception of chemical,particulate, and/or microbiological contaminants. The use of themechanical locking assembly of the filter housing without the need forexcess force and tight tolerances essential in prior art filter housingsmakes for easy and frequent filter changes and optimal filterperformance. The filter housing assembly of the present inventionprovides simplified filter changes to minimize process downtime andwithout recourse to tools. A simple push mechanism actuates theself-driving release and change over means that hold and release thefilter housing sump or filter cartridge, and provides influent shutoffmeans to prevent leaking and spillage. A floating lock or sliding lockresponsive to an axial insertion force from the filter cartridge (forembodiments having ingress and egress ports extending axially upwardsfrom the filter cartridge) or responsive to a radial insertion forcefrom the filter cartridge (for embodiments having ingress and egressports extending radially from the filter cartridge) moves in the firstinstance, perpendicular or radially to the axial motion of the sump, oraxially or parallel to the filter cartridge axis when the filtercartridge motion is radially inwards, and allows a specific filter keyto insert within the floating lock. Once inserted, the floating lockretracts towards its original position under a resilient force, such astwo springs in tandem, or other complementary resilient mechanismkeeping the floating lock under retraction tension when moved from itsinitial position. The filter key and floating lock combination allowsfor the identification of specific filter models and may be configuredto reject all but specific filter types.

Removal of the filter cartridge is performed in the same manner. Foringress and egress ports located in the axial direction, an axialinsertion force causes the floating lock to move radially, which allowsthe filter key to be removed from the floating lock. For ingress andegress ports located in a radial direction, a radial insertion forcecauses the floating lock to move axially, which allows the filter key tobe removed from the floating lock. An extraction force provided byspring tension, or the like, helps push the filter cartridge out of itsbase. Fluid shutoff and locking mechanisms are initiated by the force onthe filter cartridge at the commencement of the filter changingprocedure.

The present invention is described below in reference to its applicationin connection with, and operation of, a water treatment system. However,it should be apparent to those having ordinary skill in the art that theinvention may be applicable to any device having a need for filteringliquid.

FIG. 1A is a top exploded view of one embodiment of the filter assemblyof the present invention. In this embodiment, the ingress and egressports are presented in the axial direction. The filter assembly isfixably secured in a position within an operating environment requiringfluid filtration, such as attached to an internal sidewall of arefrigerator, although certainly other operating environments may beenvisioned, and the filter assembly may be used in any number ofenvironments where the filter assembly has access to, and can be placedin fluid communication with, influent and effluent fluid access ports.For illustrative purposes only, application to the filtering of waterbeing piped into a refrigerator is discussed.

In a first embodiment, a filter housing assembly 200 comprises theremovable, detachable filter cartridge or sump of the filter assemblyfrom a filter base 100. Filter housing assembly 200 includes a filterhousing 1, which encloses filter media 8, a filter head 2 that attachesat one end to filter housing 1, and attaches at the other end to afilter manifold 3 and non-floating port 11. A filter key 5 is attachedto filter manifold 3. Filter base 100 includes non-floating port 11,floating lock 12, and rear plate 13. Filter head 2 secures in awater-tight fit to filter housing 1. The attachment scheme may be madeby a water-tight screw fit, bond, weld, or other water-tight fasteningmechanism commonly used in the art for sealing adjoining components,typically adjoining plastic components. As discussed in further detailbelow, filter key 5 is connected to filter manifold 3. Filter key 5 maybe formed as one piece with filter manifold 3, or may be securelyattached by other methods, such as bonding, welding, press fit, frictionfit, or the like. Filter key 5 may also be removably attached forreplacement by an end user. Filter manifold 3 is attached to filter head2. Filter media 8 is located in filter housing 1. Each end of filtermedia 8 is secured by a cap that facilitates the direction of the fluidbeing treated by the filter. At one end, filter media 8 is secured by aclosed end cap 7, and at the other end by open end cap 6. Filter media 8may be any filter media known in the art, and preferably, is a carbonblock filter. It is typically shaped in a similar fashion as filterhousing 1, which in the preferred embodiment is cylindrical. Open endcap 6 is designed to interface and be in fluid communication with filterhead 2.

In a second embodiment, as depicted in FIG. 12A, a filter housingassembly 200′ comprises a radially removable, detachable filtercartridge or sump of the filter assembly from a filter base (not shown).Filter housing assembly 200′ includes a filter housing 1′, whichencloses filter media, a filter head 2′ that attaches at one end tofilter housing 1′, and attaches at the other end to a filter base havinga non-floating port (not shown). A filter key 5′ is attached to eitherfilter head 2′, filter housing 1′, or both. Alternatively, it may alsobe attached to a filter manifold. FIG. 12B depicts a top view of filterhousing assembly 200′ with radially projecting ingress and egress ports41 a′,b′ respectively.

FIG. 12C depicts a perspective view of filter housing assembly 200′radially attached to filter base 100′, which includes non-floating port11′, floating lock 12′ (not shown), and rear plate 13′. Filter head 2′secures in a water-tight fit to filter housing. As depicted in FIG. 12B,filter key 5′ may be formed securely attached to the filter housingassembly 200′ by such methods as bonding, welding, press fit, frictionfit, or the like. Filter key 5′ may also be removably attached forreplacement by an end user.

In another embodiment, filter housing 1 may include strengthening ribs16 longitudinally located on the filter housing outer surface. FIG. 1Cdepicts a perspective view of filter housing assembly 200 with a row ofstrengthening ribs extending at least partially down the outer surfaceof filter housing 1. Strengthening ribs 16 also function as a guide forinserting filter housing assembly 200 into a shroud (not shown) that maybe part of the installation assembly for ensuring proper alignment withfilter base 100. Strengthening ribs 16 is preferably integral withfilter housing 1, but may also be attachable as a separate componentpart. Ribs 16 may extend the full length of filter housing 1, or asshown, may extend to an intermediate point between filter housingassembly 200 end caps 6, 7.

Filter housing assembly 200 (as well as filter housing assembly 200′) isa finished assembly including filter housing 1, which encompasses filtermedia 8 by closed end cap 7 at one end, and open end cap 6 at the other.Generally, O-ring seals, such as O-ring seal 9, are used to preventwater leakage where different components are expected to mate.

Filter manifold 3 and filter key 5 are joined with filter head 2, andsecured to filter housing 1 to form the assembled filter housingapparatus 200. These components may be integral, permanently secured, orremovably attached to one another, and to filter head 2. FIG. 1B is aside plan view of the axial ingress and egress port embodiment of thefilter assembly of the present invention. A complementary arrangementmay be made for the radial ingress and egress port embodiment of FIG.12.

FIG. 2A is a perspective view of filter key 5, and is also applicable tofilter key 5′ of the radial embodiment. FIG. 2B is a lateral side viewof filter key 5. As previously noted, in the axial port embodiment, thebottom of filter key 5 is attached to filter manifold 3 by any number offastening schemes, or may be integrally formed with filter manifold 3.FIG. 2C depicts a groove 51 that is preferably shaped to receive acomplementary protrusion on filter manifold 3 in the axial portembodiment, and is preferably shaped to receive a dovetail protrusion;however, other connecting, complementary shapes are not excluded. Asimilar attachment scheme is available for the radial port embodiment,as depicted in FIG. 12B, with groove 51′ attached to or formed withfilter head 2′, or filter assembly 200′. The groove shapes may vary asdiscussed below, provided they secure filter key 5, 5′ to the respectivefilter housing structure.

FIG. 2G depicts a slotted groove 51 b that is not a dovetail joint.Slotted groove 51 b may include a wider upper portion 51 c to moresecurely affix filter key 5 to filter manifold 3. The connection offilter key 5 with filter manifold 3 may be bonded, sonic welded, pressfitted, friction fitted, or the like. As depicted in the axial portembodiment, groove 51 is shaped to accept a snap feature for a press orsnap fit located on filter manifold 3. In this manner filter key 5 maybe removably attached to filter manifold 3. Similarly, filter manifold 3may be designed to be removably attached to filter head 2. Thus, thedesign has more flexibility to introduce and accommodate different keyconfigurations, which can be used to designate specific filter types,and purposely reject other filter types. Filter key 5′ may be removedfrom filter housing assembly 200′ in a similar manner.

Additionally, the filter keys 5, 5′ may include an angled, ramp segment59 a on at least its bottom edges where the filter key slideably mateswith the top surface of the adjoining structure, which in the axial portembodiment is with filter manifold 3 or filter head 400. FIG. 2H is aside view of a filter key depicting angled ramp segment 59 a, which atleast partially extends the length of the bottom surface of the filterkey. Angled ramp 59 a is located at one end of the bottom edges of thefilter key and extends into the filter key main body 5 a. FIG. 2Idepicts a perspective view of filter head 400 with complementary angledramp segments 59 b for mating with angled ramp segments 59 a of thefilter key. Angled ramp segment 59 a mateably adjoins complementaryangled ramp segment 59 b to interlock and assist in securing filter key5 to filter head 400. For the two piece design utilizing filter manifold3, complementary angled ramp segments 59 b are formed on the top surfaceof filter manifold 3. FIG. 2J depicts a side view of a partial sectionof filter head 400 showing mating protrusion 321 for interlocking withslotted groove 51 b, and complementary angled ramp segments 59 b.

For the axial port embodiment, FIG. 4A depicts a perspective view offilter manifold 300. Port 310 is shown off center of filter manifold300. FIG. 4A depicts the filter manifold without extension supportmembers. Preferably, port 310 is an outlet port; however, the presentinvention is not limited to a specific ingress and egress location, andmay have these ports interchanged. When port 310 is used as an egress oroutlet port, filter manifold 300 takes fluid from filter media 8 throughthe center port of open cap 6, and directs fluid flow radially outwardsfrom the axial center to port 310. In this embodiment, the ingress portis located on filter head 2. By locating the ingress and egress portsoff axis, filter housing assembly 200 has a more robust design, withenhanced structural integrity for mounting to the filter base, and forremaining fixably in place during attachment. Referring to FIGS. 4A-4C,in a preferred attachment scheme for filter key 5, a protrusion 32 or320 is formed on or near the center line of filter manifold 3 or 300.Protrusion 32 or 320 is preferably a rectangular shaped segmentextending above circular center portion 33 or 330. Protrusion 32 allowsfor precise alignment of filter key 5, while providing a robustconnection. A dovetail shape, press fit, or friction fit interconnectionbetween protrusion 32 and groove 51 of filter key 5 permits the user toremove and replace filter key 5. This allows for the designation ofspecific filter keys, and correspondingly, specific filter cartridges.Protrusion 32 or 320 may be integrally formed with filter manifold 3 or300, respectively, or may be separately fabricated and attached by bond,weld, press fit, friction fit, or other suitable means known in the art.Preferably, protrusion 32 or 320 has a dovetail shaped surface formating with complementary groove 51 of filter key 5.

In the embodiment depicted by FIGS. 4B and 4C, protrusion 32 may be onan extension support 34. FIG. 4B depicts a top level view of filtermanifold 3, showing extension support 34 extending longitudinally orradially outward from center portion 33, along a radius. Extensionsupport 34 supports optional shroud 4 that covers and protects filterhead 2.

Filter manifold 3 or 300 seats within, and attaches to, filter head 2.FIG. 5A depicts a side view of the axial port embodiment of filter head2. Filter head 2 is shown with off-center port 21. In this manner, port21 of filter head 2 and port 31 of filter manifold 3 are both off-centerand parallel to one another about a plane that approximately intersectsthe center point of filter head 2. As shown in FIGS. 1, 4, and 5, arecessed portion 22 formed about the center point of filter head 2receives center portion 33 of filter manifold 3. If extension support 34is used with filter manifold 3, when filter manifold 3 is insertedwithin filter head 2, extension support 34 is situated approximatelyperpendicular to the plane formed by ports 21 and 31. Extension support34 provides at each end a snap fit design for shroud 4. FIG. 5B is abottom perspective view of the filter head. FIG. 5C is a top perspectiveview of filter head 2 depicting recess portion 22.

Filter head 210 depicts another axial port embodiment as shown in FIGS.5D-5F. In this embodiment, as depicted in the top perspective view ofFIG. 5F, on the top surface of filter head 210 is a curved receivingboss or support member 230 located on one side of the center point, andtwo parallel, lateral support members 240 a,b located opposite curvedboss 230 on the other side of the center point of filter head 210. Thesestructural support members are used to align filter key 5 to filter head210, and help secure filter key 5. This filter head may be used inconjunction with the filter manifold 300 without extension supports, asdepicted in FIG. 4A. Structural support member 230 provides a physicalstop for filter key 5, which typically slides on protrusion 32 providedby filter manifold 300. Lateral support members 240 a,b are used toalign filter key 5, and prevent it from inadvertent shifting. FIG. 5E isa bottom perspective view of filter head 210. FIG. 5D is a side view offilter head 210.

In another embodiment, filter head 2, 210 may be integral with filtermanifold 3, 310, such as for example, a one piece construction in theform of a single injected molded piece, or a two piece construction withfilter manifold 3, 310 welded, fused, or otherwise permanently attachedto filter head 2, 210 as a subassembly. FIG. 5G depicts a one-piece orintegrated filter head/filter manifold construction 400 having ingressand egress ports 410 a,b. Protrusion 420 is preferably a shaped segmentextending above, and off axis from, the circular center of filter head400. Protrusion 420 allows for precise alignment of filter key 5, whileproviding a robust connection. A dovetail shape, press fit, or frictionfit interconnection between protrusion 420 and groove 51 of filter key 5permits the user to remove and replace filter key 5. FIG. 5H is a sideview of an integrated, one-piece filter head 400. Cylindrical wall 424is sized to receive the open end cap 6 of filter housing 1. Cylindricalwall 426 is off the axial center of filter head 400 and is configured toreceive the center axial port of end cap 6, redirecting fluid flow offthe axial center such that port 410 b is within cylinder 426, and port410 a is outside of cylinder 426. This redirection of fluid flowperforms a similar function as filter manifold 3, 310 without the needof aligning the center axial port of end cap 6 with a filter manifoldaperture. Ports 410 a,b each have a respective aperture 410 c,d forfluid flow. The ports are terminated in respective fluid-sealed topsurfaces 411 a,b so that fluid can only flow through the apertures 410c,d. FIG. 5I is a bottom view of the integrated, one-piece filter headof FIG. 5G, depicting off axial center cylinder 426 for receiving a portof open end cap 6 of the filter cartridge. A comparison to FIGS. 5B and5E which depict perspective views of the underside of filter head 2, 210respectively, with FIG. 5I, demonstrates the absence of an axiallycentered cylinder for receiving the port from open end cap 6 in theintegrated filter head 400 design.

Filter manifold 300 includes an off-center port 310, as well as a centerportion 330 that fits securely within recess 220 of filter head 210.Protrusion 320 receives the groove from filter key 5. In thisembodiment, when filter key 5 is slidably inserted within protrusion320, structural support member 230 and lateral structural supportmembers 240 a,b secure filter key 5. The curved portion of structuralsupport member 230 forces filter key 5 to be inserted in one directiononly. An added boss 232, located on the top of filter head 210 andcentered between lateral support members 240 a,b may be employed toserve as a lock or snap fit for filter key 5. Additionally, in anotherembodiment, structural support member 230 may be formed with a smallaperture 235 located directly away from the center point of filter head210 at its base where support member 230 meets the top portion of filterhead 210. This small aperture 235 is designed to receive a protrudingmaterial or locking nub or tab 53 placed at, or formed with, thecorresponding end portion of filter key 5 on the lower end of a lateralside. Locking nub or tab 53 on filter key 5 is inserted within smallaperture 235 on the curved portion of structural support member 230 andprevents axial removal of filter key 5 away from filter head 210. FIGS.2A-2F show locking nub 53 located on the bottom portion of a lateralside of filter key 5. FIG. 5D is a side view of filter head 210depicting aperture 235 for receiving filter key 5.

Filter keys 5, 5′ are interchangeable, and include at least onelaterally extending finger 52, and preferably a plurality of extendingfingers, as depicted in FIGS. 2A-2F. FIG. 2C is a bottom perspectiveview of filter key 5, 5′. In a first illustrative embodiment, filter key5 is shown with ten laterally extending fingers 52. Fingers 52 arepreferably constructed of the same material as, and integrally formedwith, base 55 of filter key 5. However, the fingers may also beremovably attached, and the filter key design is not limited to anintegrally formed construction. The laterally extending fingers 52 mayform a number of different configurations. In the illustrativeembodiment, there is a uniform gap 54 between each finger 52. In otherconfigurations, a finger may be missing on one or both sides of filterkey 5, and gap 54 may be wider in some places than in others. Using adigital 1, 0 designations to indicate a finger (1) or a gap (0), it ispossible to have many different configurations for a filter key. Theconfiguration as shown in FIG. 2E would be designated on each side as101010101. As a separate example, for a designation of 100010101, thiswould represent a lateral finger (1) followed by a wide gap (000), andthen a finger (1) followed by a gap (0) and a finger (1) followed byanother gap (0), and one last finger (1). The present invention is notlimited to any particular finger/gap order. Additionally, it is notnecessary for the finger/gap configuration on one side of filter key 5to be symmetric with the finger/gap configuration on the opposite side.By having different finger/gap configurations, it is possible to make amechanical key identifier for the specific filter housing assembly beingemployed. Filter keys 5, 5′ may also be color-coded to facilitateidentification for different filter cartridges or housing assemblies. Itmay also be textured, mirrored, transparent, translucent, materiallymodified, or having a conductively signature, or any combinationthereof, for identification purposes. More importantly, aside fromidentification of the filter housing assembly, a particular filter keyfinger/gap configuration will only allow for the use of a specificfilter housing assembly in a given system.

Fingers 52 of the filter key are strength bearing members, used to matewith, or interlock with, corresponding drive keys 123 a,b located onlongitudinal sides of floating lock 12 as depicted in FIG. 3. There mustbe at least one drive key on floating lock 12, 12′ that corresponds to,and lines up with, at least one finger on the filter key, so that whenthe filter key is inserted to mate with floating lock 12, 12′, the drivekeys slidably contact the fingers and the floating lock is shiftedlongitudinally an incremental amount to allow fingers 52 on the filterkey to traverse between the gaps 122 on the floating lock. Once fingers52 have passed between the corresponding gaps on the floating lock,which is slidably restrained under tensional forces, the floating lockis partially returned towards its original position by the tensionalretraction forces so that at least one finger on the filter key alignsor interlocks with at least one drive key on the floating lock, and thealignment resists any direct outward, axial extraction forces.

Each finger 52 of filter key 5 includes a slanted face 58 as depicted inFIGS. 2A and 2F. These angled features are made to slidably contactcomplementary slanted edge or angled features 121 a,b of drive keys 123a,b of floating lock 12 shown in FIGS. 3A and 3E. During insertion offilter key 5, the sliding contact of the angled feature of the filterkey's fingers transversely shifts floating lock 12 off of its initialposition, and allows the fingers of filter key 5 to be inserted withingaps 122 between the drive keys 123 a,b.

A perspective view of the floating lock 12 is depicted in FIGS. 3A and3B. This view is also applicable to the floating lock used for theradial port embodiment. Floating lock 12 has angled-faced fingers,protrusions, or drive keys 123 a,b and gaps 122 that may reciprocallycorrespond to fingers 52 and gaps 54 located on the filter key 5, 5′. Itis not necessary for the drive key/gap configuration of floating lock 12to be exactly complementary to the finger/gap configuration of filterkey 5. It is only necessary that floating lock 12 is able to fullyreceive the inserting filter key 5 when filter housing assembly 200 isaxially inserted into filter base 100. Each drive key 123 a,b offloating lock 12 is shaped with a receiving wedge 129 a,b, respectively,opposite slanted edge 121 a,b to capture fingers 52 of filter key 5.Fingers 52 may have a cross-sectional diamond shape to facilitate thecapture by the drive key receiving wedge 129 a,b. Drive keys 123 a,b areplaced on at least one longitudinal side of floating lock 12, asdepicted in FIGS. 3D and 3E. Underneath and centered between drive keys123 a,b is a row of position stops 125. Position stops 125 precludefingers 52 from extending any further during insertion. There need notbe a position stop 125 for each drive key 123 a,b, provided there is atleast one position stop 125 to prohibit over insertion of filter key 5.Position stops 125 also include a slanted or angled face 126 forslidable contact with slanted face 58 of fingers 52 on filter key 5.Position stops 125 are shown as a row of jagged edges, but do not haveto correspond one-for-one with drive keys 123 a,b.

Upon insertion, when fingers 52 of filter key 5 contact drive keys 123a,b, floating lock 12 shifts away from its initial position, againstretraction forces, and moves according to the contacting angled edges 58and 121. Once wings 56 a,b of fingers 52 clear lip 127 a,b of drive keys123 a,b, floating lock 12 is not prohibited from reacting to theretraction forces, and moves slightly back, towards its originalposition where diamond shaped wings 56 a,b are then trapped by receivingwedges 129 a,b. This position locks filter key 5 to floating lock 12resisting any a direct axial extraction force.

There is a gap or space 124 between the bottom most portion of drive key123 a,b and top most portion of position stop 125. Upon extraction, whenwings 56 a,b of fingers 52 are pushed within this gap or space, there isno structure preventing floating lock 12 from responding to thetensional retraction forces acting on it. Thus, floating lock 12 is freeto respond to the retraction forces, and will tend to move towards itsinitial position. This will align fingers 52 of filter key 5 within gaps122 of floating lock 12 and allow for easy extraction of filter housing200.

In order to extract filter housing assembly 200, a user again pushesaxially inwards on the filter housing assembly, which releases wings 56a,b on filter key 5 from drive keys 123 a,b. This frees floating lock 12to return to towards its original position, and locates fingers 52 onfilter key 5 at gaps 122 of floating lock 12. Filter housing assembly200 can now be freely extracted from filter base 100. Resilient members1110 within shut-off stanchions 1101 a,b of non-floating port 11 assistin pushing or extracting filter housing assembly 200 away from filterbase 100.

FIG. 9A is a perspective view of non-floating port 11, which works intandem with rear plate 13 or rear plate 1300 to hold floating or slidinglock 12 in place while allowing it to freely move longitudinally off itscenter position and back to its center position during the insertion andextraction of filter housing assembly 200. Similarly, FIG. 12C depicts aperspective view of the non-floating port working in tandem with rearplate 13′ for the radial port embodiment. As discussed further herein,non-floating port 11 will also hold floating lock 1200 and floating lock1212 of FIG. 8. For simplicity, reference is made chiefly to theinteraction of non-floating port 11 with floating lock 12, although theapplicability of non-floating port 11 includes usage with floating lock1200 and 1212 as well. Non-floating port 11 includes a protrudingencasement 1102, larger than floating lock 12, and made to enclosefloating lock 12 therein. Encasement 1102 prevents over-travel offloating lock 12, and protects it when installed from extraneous,unintended movement. FIG. 9B is a top plan view of non-floating port 11.Stanchions 1101 a,b are located on opposite sides of encasement 1102.Similarly, stanchions 1101 a′, b′ are located on opposite sides ofencasement 1102′ of the radial port embodiment of FIG. 12C.

Ports 1103 represent the ingress and egress ports for the fluid.Shut-off stanchions 1101 a,b include shutoff plugs 14, which act asvalve seals to stop fluid flow when the filter cartridge is beingremoved. Shut-off stanchions 1101 a,b are preferably cylindrical inshape, containing spring activated, O-ring sealed plugs for sealing theingress and egress lines during filter cartridge removal. In a preferredembodiment, rear plate 13 is snap fitted into non-floating port 11. Inorder to accommodate this, snap fittings 1105 are shown on non-floatingport 11 that receive a corresponding fitting 135 on rear plate 13.

Referring to FIG. 1, floating lock 12 is supported by non-floating port11 and rear plate 13. FIG. 10A is a top plan view of one embodiment ofrear plate 13 of the present invention. FIG. 10B depicts a bottomperspective view of rear plate 13. Rear plate 13 secures floating lock12 within a support structure in non-floating port 11. Rear plate 13 ispreferably attached by snap fit to non-floating port 11, although otherattachment schemes known in the art may be easily employed, such asbonding, welding, and assorted mechanical fasteners. In FIG. 12C, rearplate 13′ is depicted as a snap fit attachment. Rear plate 13 is formedwith extensions 132 on each end, and shaped gaps 133 therebetween. Inthe radial port embodiment, rear plate 13′ includes one extension 132′,and a snap fit aperture at the opposite end. Gaps 133 are shaped to goaround shut-off stanchions 1101 a,b of non-floating port 11, or in thecase of the radial port embodiment, the width of the center aperture131′ is such that it fits between stanchions 1101 a′,b′. In bothembodiments, rear plate 13, 13′ includes a center aperture 131, 131′respectively that allows for longitudinal movement of floating lock 12.Floating lock 12 may include an extension member opposite the faceconfigured with fingers and gaps, in order to permit resilientcomponents, such as helical or torsion springs to act upon it. FIGS. 3Cand 3E are side views of the floating lock showing extension member 128.FIG. 3B is a perspective view of the floating lock 12 with extensionmember 128. FIG. 8E depicts floating lock 1212 with extension member1280. In these embodiments, the extension member is acted upon byresilient devices held by the rear plate.

FIG. 10C is a top plan view of another embodiment of the rear plate 1300of the present invention. In this embodiment, the topside of rear plate1300 includes a domed, slotted cover 1302 over the center aperture.Cover 1302 is formed to encase springs or other resilient members aboutthe extension member 128 extending from floating lock 12. Dome 1302includes a slot 1304 that is made to receive the extension member 128from floating lock 12. Slot 1304 helps retain linear movement offloating lock 12 inside dome 1302. In this embodiment, two complementaryresilient members, such as springs, would reside on each side of theextension member 128 of floating lock 12. A dome is also introduced inthe radial port embodiment as shown in FIG. 12C.

One resilient member preferably applies force on the floating lockextension member in one direction, while the other resilient memberapplies force to the floating lock extension member in the oppositedirection. In this manner, no matter which way floating lock 12 is movedor shifted, a retraction force presents itself to return floating lock12 to its original, centered position.

At all times during insertion, the filter housing assembly is underextraction forces that tend to push the housing out of the filter base.These extraction forces result from resilient members in each shut-offstanchion 1101 a,b, 1101 a′,b′ of non-floating port 11 (shown forexample in FIG. 9B) that force shutoff plugs 14 into position in orderto block the ingress and egress ports. Preferably, the extraction forceson shutoff plugs 14 are provided by a spring 1110 in each port, althoughother resilient members may be used to provide a similar result.Inserting the filter housing assembly into the filter base works againstthese extraction forces, and pushes shutoff plugs 14 further up eachshut-off stanchion 1101 a,b of non-floating port 11. This allows forfluid ingress, while keeping the filter housing assembly under theconstant extraction force.

Protective port shroud 4 may be placed over filter head 2, to protectthe floating lock 12 and filter key 5 mechanism from damage and debris.Shroud 4 is preferably supported by the extension supports on the filtermanifold.

FIGS. 6A and 6B are exploded views of another embodiment of the filterassembly of the present invention, showing the combination of filtermanifold 300, filter key 500, and filter head 210. Filter key 500 isdepicted without a locking nub or tab; however it may include a lockingnub to facilitate attachment to the filter head. FIG. 7F depicts filterkey 590 with locking nub or tab 501. Locking nub 501 is located at thebase of filter key 590. In this embodiment, filter key 500 or 590 andfilter manifold 300 are modified such that floating lock 1200 or 1212 ofFIG. 8 is slidably shifted by the interaction wings 560 a,b of anextended boss 550 on filter key 500 or 590 with drive keys 1210 a,b offloating lock 1200.

Filter key 500 or 590 is inserted within floating lock 1200 through theaxial insertion of the filter housing assembly into the filter base.Hammerhead shaped wings 560 a,b on fingers 520 of filter key 500 anddrive keys 1210 a,b on floating lock 1200 or 1212 slidably contact oneanother, causing a transverse motion of floating lock 1200 or 1212perpendicular to the axial motion of insertion. In this manner, floatinglock 1200 or 1212 is shifted longitudinally, in a direction radiallyrelative to the filter housing assembly axis. Fingers 520 of filter key500 are positioned within the gaps 1220 on floating lock 1200 or 1212.Once filter key 500 or 590 is inserted, floating lock 1200 or 1212 isreturned partially towards its original position by retracting tensionalforces, preferably by complementary spring forces, so that the fingerson floating lock 1200 or 1212 align directly with fingers 520 on filterkey 500 or 590, thus preventing a direct extraction force from removingthe filter housing assembly from the filter base.

FIG. 7F depicts a top perspective view of filter key 590. At one end offilter key 590 is an upwardly extended angled boss 550. Boss 550 risesabove horizontal plane 570 created by the top portion of fingers 520,and is angled toward fingers 520, with its highest point at one end offilter key 500. Boss 550 angles downward from its highest point towardsfingers 520. Preferably, boss 550 is an upwardly facing triangular orwedge shaped design having wings 560 a,b for interaction with drive keys1210 a,b, respectively, on floating lock 1200. FIG. 7E depicts an endview of filter key 500 showing a hammerhead shaped boss 550 rising aboveplane 570 created by fingers 520, and wings 560 a,b extending laterallyfrom boss 550 resembling what may be considered a hammerhead shape. Thepurpose of wings 560 a,b is to contact corresponding angled drive keys1210 a,b on floating key 1200.

A perspective view of the complementary floating lock 1200 is depictedin FIG. 8A. The only difference between floating lock 1200 of FIG. 8Aand floating lock 1212 of FIG. 8E is the addition of an extension member1280 on floating lock 1212. Floating lock 1200 has fingers 1230 a,b andgaps 1220 that may reciprocally correspond to fingers 520 and gaps 540located on filter key 500 or 590. It is not necessary for the finger/gapconfiguration of floating lock 1200 to be exactly complementary to thefinger/gap configuration of filter key 500 or 590. It is only necessarythat floating lock 1200 is able to fully receive the inserting filterkey 500 when the filter housing assembly is axially inserted into thefilter base. Furthermore, once floating lock 1200 is subjected toretraction forces acting to return it partially towards its originalposition, it is necessary that at least one finger on filter key 500 or590 vertically align with at least one finger on floating lock 1200 or1212 preventing any extraction without further shifting of floating lock1200 or 1212.

Using floating lock 1200 and filter key 500 as illustrative examples,upon slidable contact of wings 560 a,b on filter key 500 and drive keys1210 a,b on floating lock 1200, floating lock 1200 moves in a transversemotion, perpendicular to the motion of insertion. In this manner,floating lock 1200 is shifted either longitudinally, in a directionradially relative to the filter housing assembly axis, or radially, in adirection longitudinally relative to the filter housing assembly radius.Fingers 520 of filter key 500 are positioned within the gaps 1220 onfloating lock 1200. Once filter key 500 is inserted, floating lock 1200is returned partially towards its original position by retractingtensional forces, preferably by complementary spring forces, so that thefingers on floating lock 1200 align directly with fingers 520 on filterkey 500, thus preventing a direct extraction force from removing thefilter housing assembly from the filter base.

Fingers 1230 a,b are preferably constructed of the same material asfloating lock 1200 and integrally formed therewith. However, fingers1230 may also be removably attached, and the floating lock design is notlimited to an integrally formed construction. Additionally, the presentinvention is not limited to any particular finger/gap order. It is notnecessary for the finger/gap configuration on one side of floating lock1200 to be symmetric with the finger/gap configuration on the oppositeside. Floating lock 1200 is responsive to tensional forces, such ascomplementary springs acting on it from two separate directions toprovide resistance longitudinally. Floating lock 1200 effectively moveslongitudinally when acted upon by filter key 500, and is forced toreturn partially towards its original position after fingers 520 offilter key 500 have traversed through gaps 1220. Upon partialretraction, fingers. 520 are aligned behind or underneath fingers 1230of floating lock 1200. FIG. 8B is a top view of floating lock 1200showing laterally extending fingers 1230 a,b and adjacent gaps 1220between the fingers.

FIG. 8C is a cross-sectional view of floating lock 1200, depicting drivekey 1210 a, which is located at one end of floating lock 1200 onlongitudinal or side panel 1240. Drive key 1210 a is opposite a similardrive key 1210 b (not shown), which is located on the oppositelongitudinal panel of floating lock 1200. Both drive keys are designedto have an angled face for slidably interacting with wings 560 a,b ofboss 550 on filter key 500. Each drive key is preferably integrallyfabricated with floating lock 1200; however, the drive keys may befabricated separately and attached to the longitudinal panels offloating lock 1200 by attachment means known in the art. As shown inFIG. 8C, below drive key 1210 a is a position key or physical stop 1250,preferably formed with the supporting lateral wall 1260 of floating lock1200. As shown in FIG. 8B, position key 1250 is situated between drivekeys 1210 a,b. Position key 1250 may be integrally formed with lateralwall 1260, or may be separately attached thereto by any acceptable meansin the prior art, such as bonding, welding, gluing, press fitting, andthe like. Position key 1250 acts as a physical stop to ensure againstover travel of floating lock 1200. Position key 1250 is situated belowdrive keys 1210 a,b by a distance designed to accommodate the insertionof boss 550 of filter key 500. Upon insertion of filter key 500 intofloating lock 1200, boss 550 traverses through gap 1270 in floating lock1200 formed by the space between drive keys 1210 a,b. Wings 560 a,b ofboss 550 extend outward relative to the width of boss 550, traversingbetween lateral wall 1260 and drive keys 1210 a,b. In this manner, wings560 a,b retain floating lock 1200 from retracting back to its originalposition while boss 550 is being inserted. At all times, floating lock1200 is under the retraction force of resilient members, such as tandemsprings, or the like, tending to keep floating lock 1200 its originalposition, which is preferably a centered position. During insertion offilter key 500, wings 560 a,b interact with drive keys 1210 a,b to shiftfloating lock 1200 longitudinally off-center while under the resilientretraction forces. Upon full insertion, when boss 550 reaches andcontacts position key 1250, wings 560 a,b are no longer held by drivekeys 1210 a,b because the length of drive keys 1210 a,b is shorter thanthe length of boss 550. At this point in the insertion process, thetensional retraction forces shift floating lock 1200 towards itsoriginal position.

Once wings 560 a,b reach position key 1250, and the user releases theinsertion force initially applied on the filter housing assembly, theextraction forces from shutoff plug springs 1110 dominate. These forcespush the filter housing assembly axially outwards, away from floatinglock 1200. Since wings 560 a,b are no longer bound between drive keys1210 a,b and lateral wall 1260, floating lock 1200 will tend to shiftlongitudinally, partially towards its original position as filter key500 moves slightly axially outwards. At this point, wings 560 a,binteract with edge angles 1280 a,b to push away from the centerposition, shifting filter key 500, and combining or contacting with face1300 a,b to keep the filter housing from retracting. FIG. 8D depicts anexploded view of drive key 1210 a with edge angle 1290 a and face 1300a.

Fingers 520 of filter key 500 are now aligned with fingers 1230 offloating lock 1200 and remain in contact in a vertical plane in theaxial direction, prohibiting extraction of the filter housing assemblyfrom the filter base.

It is envisioned that the preferred embodiment of the present inventionwould be disposed in a refrigerator, most likely within the door. Usingthe axial port embodiment as an example, the output of the filterassembly may be selectively coupled to a water dispenser or an icedispenser. The water source to the refrigerator would be in fluidcommunication with filter base 100, and prohibited from flowing whenfilter housing assembly 200 is removed from filter base 100. Shutoffplugs 14 in stanchions 1101 a,b seal fluid flow until filter housingassembly 200 is inserted in filter base 100. Upon insertion, fluid wouldflow to the filter housing assembly and filter water would be returnedfrom the filter housing assembly.

All parts of the filter housing assembly 200 and filter base 100 may bemade using molded plastic parts according to processes known in the art.The filter media may be made from known filter materials such as carbon,activated carbons, malodorous carbon, porous ceramics and the like. Thefilter media, which may be employed in the filter housing of the instantinvention, includes a wide variety of filter media capable of removingone or more harmful contaminants from water entering the filter housingapparatus. Representative of the filter media employable in the filterhousing include those found in U.S. Pat. Nos. 6,872,311; 6,835,311;6,797,167; 6,630,016; 5,331,037; and 5,147,722. In addition, the filtercomposition disclosed in the following published applications may beemployed as the filter media: U.S. 2005/0051487 and U.S. 2005/0011827.

The filter assembly is preferably mounted on a surface in proximity to asource of water. The mounting means are also preferably in closeproximity to the use of the filtered water produced by the filterhousing apparatus.

While the present invention has been particularly described, inconjunction with a specific preferred embodiment, it is evident thatmany alternatives, modifications and variations will be apparent tothose skilled in the art in light of the foregoing description. It istherefore contemplated that the appended claims will embrace any suchalternatives, modifications and variations as falling within the truescope and spirit of the present invention.

The invention claimed is:
 1. A filter housing assembly comprising: afilter media; a filter housing having a top, a bottom, sidewalls, and acenter axis for enclosing said filter media; said filter housing tophaving two cylindrical ports extending therefrom, each cylindrical porthaving a sidewall with an aperture and a fluid-tight sealed top surface,said cylindrical ports in fluid communication with said filter media forfluid ingress and egress, said filter housing top including a firstattachment structure for receiving a filter key, wherein said firstattachment structure forms an elongated protrusion or rail extendingaxially upwards from said filter housing top, and having an upperportion extending radially outwards perpendicular to said center axis ofsaid filter housing top, said elongated protrusion or rail slideablyengaging a connector piece or filter key that is designed to interfacewith a complementary mating filter base.
 2. The filter housing assemblyof claim 1 wherein said upper portion of said elongated protrusion orrail slidably engages with said connector piece or filter key in aradial direction perpendicular to said center axis.
 3. The filterhousing of claim 2 wherein said elongated protrusion or rail including aT-shape with a rectangular base segment having a length and width, andsaid upper portion forming a flat top surface parallel to the filterhousing top, the flat top surface having straight side facesperpendicular to the filter housing top, which extend beyond therectangular base segment width.
 4. The filter housing of claim 2 whereinsaid upper portion of said elongated protrusion or rail includesextended flanges that form an approximate T-shaped cross-section orapproximate dovetail shape for slidably mating with said connector pieceor filter key.
 5. A filter housing assembly comprising: a filter media;a filter housing having a top, a bottom, sidewalls, and a center axisfor enclosing said filter media, said filter housing top having twocylindrical ports extending therefrom, each cylindrical port having asidewall with an aperture and a fluid-tight sealed top surface, saidcylindrical ports in fluid communication with said filter media forfluid ingress and egress, said filter housing top including a firstattachment structure for receiving a filter key, wherein said firstattachment structure forms an elongated protrusion or rail extendingaxially upwards from said filter housing top, and radially outwardscentered about said center axis of said filter housing top, saidelongated protrusion or rail having a rectangular shape for slideablyengaging a filter key that is designed to interface with a complementarymating filter base; and said filter key having a top surface,longitudinal sides, and lateral sides shorter than the longitudinalsides, the filter key having on a top surface an attachment finger formating with a filter base, said attachment finger extending in adirection parallel to the filter key lateral sides, wherein theattachment finger includes laterally facing opposing side faces, whereinone opposing side face forms a first angle with the filter housing axisand the other opposing side face forms a second angle with the filterhousing axis, such that the first angle and the second angle are notequal, and the filter key having on a bottom surface an indent or groovefor slideably receiving said first attachment structure.
 6. The filterhousing assembly of claim 5 wherein said attachment finger has across-sectional diamond shape.
 7. A filter cartridge comprising: afilter media; a filter housing for enclosing said filter media, thefilter housing having a body and a top portion for forming a fluid-tightseal with the body, a filter housing center axis extending in an axialdirection about the filter housing, the filter housing top portionincluding: an ingress port; an egress port; and a filter key located onor connected to the filter housing and having a top surface, at leasttwo longitudinal sides, and at least two lateral sides, each shorterthan the at least two longitudinal sides, the filter key having aprotrusion extending in a direction parallel to the filter key lateralsides, wherein the protrusion includes on one side a slanted or angledface angled with respect to the filter housing axis, and on an opposingside a face having at least a portion being a substantially straightedge parallel to the filter housing axis.
 8. The filter cartridge ofclaim 7, wherein the protrusion includes a diamond-shaped cross-sectionin a plane parallel to the at least two longitudinal sides of the filterkey.
 9. The filter cartridge of claim 7 wherein said filter housing topportion includes a first attachment structure for receiving said filterkey, wherein said first attachment structure forms a raised protrusionor rail extending axially upwards from said filter housing top portion,and having an upper portion extending radially outwards in a directionperpendicular to said center axis, of said filter housing top portion,said raised protrusion or rail upper portion slideably engaging saidfilter key.
 10. The filter cartridge of claim 9 wherein said raisedprotrusion or rail slidably engages with said filter key in a radialdirection perpendicular to said center axis.
 11. A filter cartridgecomprising: a filter media; a filter housing for enclosing said filtermedia, the filter housing having a body and a top portion for forming afluid-tight seal with the body, an axis extending in an axial directionabout the filter housing, the filter housing including: an ingress port;an egress port; and a filter key located on or connected to the filterhousing for mating attachment to a filter base or manifold, the filterkey having a top surface, at least two longitudinal sides, and at leasttwo lateral sides shorter than the at least two longitudinal sides, thefilter key having an attachment finger extending in a direction parallelto the filter key lateral sides, wherein the attachment finger includeslaterally facing opposing side faces, wherein one opposing side faceforms a first angle with the filter housing axis and the other opposingside face forms a second angle with the filter housing axis, such thatthe first angle and the second angle are not equal.
 12. The filtercartridge of claim 11 wherein said filter housing top portion includesan attachment structure for receiving said filter key, wherein saidattachment structure forms a raised protrusion or rail extending axiallyupwards from said filter housing top portion, and having a portionextending radially outwards in a direction perpendicular to said centeraxis, of said filter housing top portion, said raised protrusion or railslideably engaging said filter key.
 13. The filter cartridge of claim12, wherein said raised protrusion or rail slidably engages with saidfilter key in a radial direction perpendicular to said center axis.